CVE-2024-20749: 
Adobe Acrobat Reader Continuous vulnerability analysis and mitigation

CVE-2024-20749 is an out-of-bounds read vulnerability affecting Adobe Acrobat Reader versions 20.005.30539, 23.008.20470 and earlier. The vulnerability was discovered by KPC of Cisco Talos and publicly disclosed on February 15, 2024. The vulnerability exists in the font file processing functionality of Adobe Acrobat Reader, specifically when processing embedded font files in PDF documents (Talos Report).

The vulnerability occurs in the processing of OpenType font format, specifically in the CFF2 (Compact Font Format version 2) table handling. The issue arises when the value of an element in the CharStringsOffset array is greater than tableLength - CharStringsIndexOffset - 5 - ((CharStringsCount+1) * CharStringsOffSize). This condition leads to an out-of-bounds read vulnerability. The vulnerability has been assigned a CVSS v3.1 base score of 5.5 MEDIUM (Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N) and is classified as CWE-125 (Out-of-bounds Read) (Talos Report).

The vulnerability can lead to disclosure of sensitive memory contents. Due to complex interactions between PDF reader and font subcomponents, especially in the presence of a JavaScript engine, the vulnerability could potentially expose sensitive information that could aid in further exploitation and bypass exploit mitigations such as ASLR (Talos Report).

Exploitation of this vulnerability requires user interaction, specifically the victim must open a malicious PDF file containing a specially crafted embedded font file. The vulnerability allows an attacker to read arbitrary memory of the process (Talos Report).

Adobe has released patches to address this vulnerability through their security bulletin APSB24-07. Users are advised to update to the latest version of Adobe Acrobat Reader (Adobe Advisory).